Canada Revenue Agency: home of the people who decide how to collect government money, the site has forms, Advance Income Tax Rulings, Income Tax Information Circulars, Income Tax Interpretation Bulletins, Income Tax Technical News, Technical Information on GST/HST and Excise, Customs Trade Administration Bulletins, Customs Memorandums and Customs Notices and other useful documents.

Department of Finance Canada: home of the people who decide how to spend government money, the site has fiscal policy publications and economic studies.